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Class 11 Waves worksheet
CBSE Physics. Wave equation, strings and pipes, harmonics, beats, speed of sound. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
A sound of frequency 200 Hz travels at 336 m/s. Its wavelength is:
- 67,200 m
- 0.60 m
- 0.84 m
- 1.68 m
Answer
(d) 1.68 m
λ = v/f
- 2.
A string with mass per unit length 0.019 kg/m is under a tension of 1,385.1 N. The speed of a transverse wave on it is:
- 270 m/s
- 72,900 m/s
- 540 m/s
- 135 m/s
Answer
(a) 270 m/s
v = √(T/μ)
- 3.
A string 0.2 m long, fixed at both ends, carries waves at 170 m/s. Its fundamental frequency is:
- 212.5 Hz
- 850 Hz
- 34 Hz
- 425 Hz
Answer
(d) 425 Hz
f = v/2L
Section B · short answer
- 4.
A wave is given by y = 1 sin(3πx − 246πt) cm, with x in m and t in s. Find the amplitude, wavelength, frequency and speed.
Answer
A = 1 cm; λ = 0.67 m; f = 123 Hz; v = 82 m/s
λ = 2π/k; f = ω/2π; v = ω/k
- 5.
A string 0.4 m long fixed at both ends carries waves at 290 m/s. Find the frequencies of its first three harmonics.
Answer
362.5 Hz, 725 Hz, 1,087.5 Hz
fₙ = nv/2L
Section C · long answer
- 6.
A string 1.1 m long with mass per unit length 0.008 kg/m is fixed at both ends under a tension of 320 N. Find (a) the wave speed, (b) the fundamental frequency and its wavelength, (c) the frequencies of the second and third harmonics.
Answer
(a) 200 m/s; (b) 90.91 Hz, λ = 2.2 m; (c) 181.82 Hz and 272.73 Hz
v = √(T/μ); f₁ = v/2L
Fresh sheets for your child
In the app, every Waves sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
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